feat: “出问题了”三栏说清问题，交作品时写一句反思，外部提示词至少 8 个字

- 对话框加“出问题了”：做了什么 / 想看到什么 / 实际看到了什么拼成一句发给 AI；
  只说“还是不行”这类的提醒一次，可以直接发
- “交这一版”先弹框问最满意的改动和理由（可以不写），存在 submission_reflection，
  批改面板显示为“学生说”，只有老师和作者本人看得到
- 粘贴外部 AI 代码时提示词至少 8 个字，可以把几轮都贴进来

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

server/src/db.ts

@@ -51,6 +51,9 @@ CREATE INDEX IF NOT EXISTS "prompt_message_prompt_level_e461b596" ON "prompt_mes
 CREATE INDEX IF NOT EXISTS "prompt_message_chain" ON "prompt_message" ("conversation_id", "created", "id", "role", "source", "prompt_level");
 CREATE INDEX IF NOT EXISTS "prompt_message_submission" ON "prompt_message" ("submission_id", "conversation_id", "created", "source") WHERE "submission_id" IS NOT NULL;
 
+-- 学生交作品时写的一句反思（最满意的改动和理由）；可以不写。删提交时跟着删
+CREATE TABLE IF NOT EXISTS "submission_reflection" ("submission_id" char(32) NOT NULL PRIMARY KEY REFERENCES "submission_submission" ("id") ON DELETE CASCADE, "content" text NOT NULL, "modified" datetime NOT NULL);
+
 -- 登录用 JWT：access token 不落库，refresh token 只存 sha256
 DROP TABLE IF EXISTS "auth_session";
 CREATE TABLE IF NOT EXISTS "auth_refresh_token" ("token_hash" text NOT NULL PRIMARY KEY, "user_id" bigint NOT NULL REFERENCES "account_user" ("id") ON DELETE CASCADE, "expire_at" datetime NOT NULL);

server/src/routes/submission.ts

@@ -120,6 +120,7 @@ router.post("/", async (c) => {
       js: z.string().nullable().optional(),
       prompt: z.string().nullable().optional(),
       message_id: z.number().int().nullable().optional(), // 关联的 assistant message
+      reflection: z.string().max(1000).nullable().optional(), // 交的时候写的一句反思，可以不写
     }),
   )
   const task = orNotFound(
@@ -131,6 +132,8 @@ router.post("/", async (c) => {
 
   const code = { html: p.html ?? null, css: p.css ?? null, js: p.js ?? null }
 
+  const reflection = p.reflection?.trim() || null
+
   const { submissionId, newUserMsgId } = tx(() => {
     let manualAsstMsgId: number | null = null
     let linkedMsg: MessageRow | null = null
@@ -203,6 +206,15 @@ router.post("/", async (c) => {
     return { submissionId: id, newUserMsgId }
   })
 
+  // 同一版再交时没写就留着上次写的
+  if (reflection) {
+    run(
+      `INSERT INTO submission_reflection (submission_id, content, modified) VALUES ($id, $content, $ts)
+       ON CONFLICT (submission_id) DO UPDATE SET content = excluded.content, modified = excluded.modified`,
+      { id: submissionId, content: reflection, ts: now() },
+    )
+  }
+
   // 只对新增的提示词做层级分类
   if (
     newUserMsgId !== null &&
@@ -540,7 +552,13 @@ router.get("/:id", (c) => {
   const id = uuidParam(c, "id")
   requireView(user, id)
   const s = orNotFound(get(`${SUBMISSION_SELECT} ${SUBMISSION_FROM} WHERE s.id = $id`, { me: user.id, id }))
-  const out = submissionOut(s)
+  // 反思只给老师和作者本人看
+  const reflection =
+    isStaff(user) || s.user_id === user.id
+      ? (get<{ content: string }>(`SELECT content FROM submission_reflection WHERE submission_id = $id`, { id })
+          ?.content ?? null)
+      : null
+  const out = { ...submissionOut(s), reflection }
   // 和同学作品一样：学生给同学打分之前不告诉作者和得分（作品展里的本来就署名）
   if (!isStaff(user) && s.user_id !== user.id && !out.my_score && !inShowcase(id)) {
     return c.json({ ...out, userid: null, username: null, score: null })

server/tests/api.test.ts

@@ -276,6 +276,34 @@ describe("提交与删除", () => {
     expect(all(`SELECT COUNT(*) AS n FROM submission_submission WHERE id != $id`, { id: otherSub })).toEqual([{ n: 1 }])
   })
 
+  test("交的时候写的反思：再交没写就保留，只有老师和作者能看，删提交时一起删", async () => {
+    makeUser("stu")
+    makeUser("mate")
+    makeUser("teacher", "admin")
+    const task = makeTask("T")
+    const stu = await client("stu")
+    const edit = await stu("POST", "/api/prompt/versions", { task_id: task, html: "<p>1", css: "", js: "" })
+    const sub = await stu("POST", "/api/submission/", {
+      task_id: task,
+      html: "<p>1",
+      message_id: edit.json.message_id,
+      reflection: "  按钮改成三个，因为五个太乱  ",
+    })
+    const id = sub.json.id
+    await stu("POST", "/api/submission/", { task_id: task, html: "<p>1!", message_id: edit.json.message_id, reflection: "" })
+    expect((await stu("GET", `/api/submission/${id}`)).json.reflection).toBe("按钮改成三个，因为五个太乱")
+    expect((await (await client("teacher"))("GET", `/api/submission/${id}`)).json.reflection).toBe("按钮改成三个，因为五个太乱")
+
+    const mate = await client("mate")
+    await mate("POST", "/api/submission/", { task_id: task, html: "<p>m" })
+    const peer = await mate("GET", `/api/submission/${id}`)
+    expect(peer.status).toBe(200)
+    expect(peer.json.reflection).toBeNull()
+
+    expect((await stu("DELETE", `/api/submission/${id}`)).status).toBe(200)
+    expect(all(`SELECT * FROM submission_reflection`)).toEqual([])
+  })
+
   test("被评分的提交只有超管能删", async () => {
     const author = makeUser("author")
     const other = makeUser("other")